Pressure switches are often used to monitor an environment for pressure levels which exceed certain values. It is also advantageous to be able to monitor an environment for pressure fluctuations or spikes. In many instances, such devices are battery operated to enhance portability and maintain a relatively small size. However, a pressure sensor operating from a battery has the problem of having a relatively short battery life because the pressure sensor normally requires a continuous power flow to function. It would be desirable to utilize a pressure switch which is rugged and can operate over a wide temperature range while assuring reliable and convenient operation.
The present invention provides a pressure switch which can operate to connect an input to an output as does a normal switch. During operation of the switch, or when the switch is in the open position, the device presents an extremely high impedance and similarly when the switch is in the closed position as in conventional switches it presents an extremely low impedance. The pressure switch operates without the use of any biasing voltage and will operate in a first high impedance mode, or open mode, and a second low impedance mode or short circuit mode.